Reentrant turbine.



R. N. EHRHART. RE'E'MTRAM" nmsma.

APPULATION FILED AUG.22. 19i0. 5963 Patfilltfifi Apr. 27, 1915.

2 SHEETS-SHEET 1.

WITNESSES: IIVVENTOR.

P544.- k. M722 ms ATTORNEY IN FACT.

THE NORRIS PETERS 60.. FHOTQ-LITHQ. WASHINGTON. Dv C R. N. EHRHART. RE ENTRANT TURBiNE.

APPLICATION FILED AUG.22, 19H).

wmm Patented Apr. 2:2 1915.

2 SHEETS$HEET 2- VJITN E5: 7 m1 VENTOR.

5 C 915A)? v BY tiv m u w- @WV \k w calw a v HIS ATTORNEY IN FACT.

THE NORRIS PETERS C0. PHOIO-LITHQ. WASHINGTON. D. c

TINTTED STATEE PATENT OFFTTCQE.

RAYMOND N. EHRI-IART, OF EDGEWOOD PARK, PENNSYLVANIA, ASSIGNOR, BY MESNEASSIGNMENTS, TO THE COLONIAL TRUST COMPANY, TRUSTEE, OF'PITTSBURGH,PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA.

It-EENTRANT TURBINE.

Specification of Letters Patent.

Patented; Apr. 27, 1915.

Application filed August 22, 1910. Serial No. 578,315.

To all whom it may concern Be it known that I, RAYMOND N. EHRI-IART, acitizen of the United States, and a resident of Edgewood Park, in thecounty of Allegheny and State of Pennsylvania, have made a new anduseful Invention in Rentrant Turbines, of which the following is aspecification.

This invention relates to turbines and particularly to rentrantturbines; that is, to turbines in which the motive fluid is redeliveredto the blades or buckets after having been discharged from them.

An object of this invention is to produce a rentrant turbine, which ismore eflicient than turbines of that type now known to me.

A further object is to produce a reentrant turbine capable of employinga working section comprising two or more rows of moving blades.

A further object is to produce a reentrant turbine, in which the motivefluid is delivered and re-delivered on the same side of a row of turbineblades or buckets.

These and other objects I attain in a turbine embodying the featuresherein described, and illustrated in the drawings accompanying thisapplication and forming a part thereof.

In the drawings, Figure 1 is a distorted transverse section, the sectionthrough the blades and working passages being taken on the line 11 ofFig. 2, and illustrates a turbine embodying my invention. Fig. 2 is adeveloped section along the line 2-2 of Fig. 1 and illustrates thearrangement of the turbine blades and vanes, the delivery andre-delivery nozzles and directing passages.

The turbine illustrated consists of a stationary easing 3, whichincloses a rotor element or wheel 41 mounted on a shaft 5, whichextends, through suitable packing glands located in the ends of theturbine casing. Two annular rows of impulse blades 6 are mounted on theperiphery of the wheel 4 in any suitable manner. A row of stationaryblades or directing vanes 7 is located between the two rows of blades 6and is mounted on a base piece 8, which is secured, in any suitablemanner, as for example, by means of screws to the stationary casing 4.Motive fluid is delivered to the first row of blades 6 by means of adelivery passage or an expansion nozzle 9, which if desired maypartially expand the motive fluid, and which communicates with a fluidadmission port 10 formed in the turbine casing 3. The port 10 maycommunicate through suitable piping (not shown) with any suitable sourceof fluid supply. The blades 6, vanes 7 and the nozzle 9 form in effect aCurtiss turbine section. The first row of blades 6 is adapted toabstract a portion of the velocity energy of the fluid delivered by thenozzle 9 and to discharge the fluid into the row of stationary blades orvanes 7 which re-direct the fluid and to deliver it to the second row ofblades 6, where the remainder of the available velocity energy isabstracted.

One of the novel features of my invention is the arrangement ofdirecting passages 11 and 12, which are formed in the turbine casing andare adapted to receive motive fluid discharged from the second row ofblades 6, and to convey it around the two rows of blades 6 and tore-deliver it to the first row of blades. The motive fluid delivered bythe nozzle 9 and discharged from the second row of blades 6 is receivedby the passage 11 and is again delivered to the first row of blades 6 byre-delivery passage or an expansion nozzle 13. The nozzle 13communicates with the delivery end of the passage 11 and is adapted topartially expand the m0- tive fluid traversing it. The motive fluiddelivered by the nozzle 13 passes through the blades 6 and vanes 7,where the available velocity energy is abstracted, and is delivered tothe directing passage 12. The directing passage 12 is showncommunicating with two re-delivery passages or expansion nozzles 14,each of which is adapted to expand the motive fluid from the pressure inthe passage 12 to exhaust pressure and to deliver it a third time to theworking blades. When the motive fluid is finally discharged by thesecond row of blades 6, all of its available energy has been abstractedand it is discharged through an exhaust port 15, provided in the turbinecasing and which communicates with a condenser or with the atmosphere,as desired. The passages 11 and 12 are so arranged that the motive fluidtraversing them travels in a substantially spiral course so that itsdirection is not abruptly reversed.

r and 12. The block 18 may be secured to thecasing by meansof bolts 21.Packing strips 22 are mounted. on the blocks 16 and 18 and areyieldingly held'against the rim of the Wheel t'for the purpose offorming a packing and preventing leakage between thewheel and the nozzleblocks. The row of blades or vanes 7 need not extend entirely around thewheel 4. The purpose of these blades, as has been described, is toredirect the fluid delivered from the first row of blades 6 and todeliver it to the second row of blades 6,- and for thisreason they needonly be'located opposite to the delivery and re-delivery nozzles. Themotive, fluid may be expanded from admission to exhaust pressure in anynumber of steps, and consequently the fluid may be re-delivered to theworking section any desired number of times. It will also be apparentthat two or more admission ports 10 may be provided in the casing 3 andthat a corresponding number'of series of directing passages andre-deliverynozzles may be employed around the wheel. I

Having thus described my invention,what I claim is: a 1. Ina turbine, arotor element provided 7 with a plurality'of rows of blades extendingradially thereof, a casing, a series of divergent fluid expandingnozzles for successively delivering motive fluid in one direction tosaid blades, and a series of passages formed toreceive the fluid leavingsaid blades and to redirect and deliver it to the successive nozzles ofthe series.

a 2. In a turbine, a rotor element provided with two rows of impulseblades extending radially thereof, a casing, a series of divergent fluiddelivery nozzles located on one side of said rotor element fordischarging motive fluid to said blades, and a series of fluid passagessubtending said blades and formed to receive the motive fluid leavingsaid blades and to convey it in a substantially spiral course aroundsaid rotor element to redirect and deliver it to the successive nozzlesof the series.

3. In a turbine, a rotor element prov1ded with a aw of ainl sandingblades, a

one end of one of the curved passages and is adapted to delivermotivefluid from its communicating passage to the rotor blades. 4. In aturbine, a rotor element provided with a row of radially extendingblades,f a

subtending said row of blades and communr eating at each end withtheblades so as to casing having a plurality of curved passages form asubstantially spiral passage for the motive fluid, a nozzle blocksecured to an inner face of the casing and having nozzles formed thereincommunicating with said passage, and a block secured to an opposite faceof the casing and having directing passages formed therein communicatingwith said curved passages.

5. In a turbine, a rotor element provided with a row of radiallyextending blades, a

casing having a curved fluid delivery passage subtending the row ofblades, for receiving fluid discharged from the blades and forredirecting and delivering it to the.

blades, and a nozzle block secured to an inner face of the casing andhaving a divergent nozzle formed therein which communicates with one endof said passage and is adapted to expand fluid issuing'from the passageand deliver it to said row of blades.

7 6. In a turbine, a rotor element provided with radially extendedblades, a casing having a curved fluid delivery passage subtending theblades and communicating at. each end with the blades so as to receivefluid therefrom,to redirect and redeliver itto the blades, a nozzleblocksecured to the inner face of the casing on one side of the bladesand having a nozzle formed therein communicating with one end of thepassage, and

a nozzle block secured to the opposite inner 7 face of the casingv onthe other side of the blades and having a directing passage formedtherein communicating with the other end of the passage. p

In testimony whereof, I have hereunto subscribed my name this 18th dayof August, 1910.

RAYMOND 'N'. EHRHART.

Witnesses i o. w. Mafia, E. N. MoCALLIsTnR.

Copies of this patent may be obtained for five cents each, by addressingthe Goininissioner of Patentl.

7 Washington, D. 0..

